Water diffusivity across human stratum corneum (SC) is independent of position in the membrane, i.e., water transport is homogeneous in this structurally heterogeneous membrane. In this study, repeated adhesive tape-stripping of the SC and concomitant measurements of transepidermal water loss (TEWL) allows facile determination of SC thickness and deduction of an apparent average water diffusion coefficient across the membrane. The results demonstrate that simple, noninvasive two-point measurements of TEWL, and cumulative SC weight removed by tape-stripping, can be used to provide accurate estimates of SC thickness and apparent water diffusivity across the membrane, in vivo in man. The results obtained are in good agreement with a more detailed analysis of the data and with previously published values using this and other, less convenient, techniques. While the approach does not permit the molecular mechanism of water diffusion across the SC to be deduced (and hence diffusivity values must be prefaced by the word "apparent"), it does lend itself to facile application at other body sites, and to diseased or (for example) penetration-enhancer perturbed skin.